1. Technical Field
The present disclosure relates to an exhaust muffler provided with a catalyst which purifies exhaust gas.
2. Related Art
Recently, regulations of exhaust gas has become stricter not only for engines for automobiles, but also for general purpose engines used for construction machineries, agricultural machineries, etc. Therefore, for example, Japanese Unexamined Patent Application Publication Nos. H7-042544, H5-256129, and S59-029721 disclose general purpose engines which have a catalyst inside an exhaust muffler.
Meanwhile, the exhaust muffler is caused to vibrate when vibration is transmitted from the engine or when an exhaust pulsation is caused by exhaust gas flowing inside the exhaust muffler. Especially, since the vibration of the general purpose engines for the construction machineries is large, an attaching part of a holding member of the catalyst attached inside the exhaust muffler may be damaged and, thus, the holding member may be dropped off or the catalyst may be dropped off the holding member.
If the holding member and the catalyst are tightly fixed inside the exhaust muffler to prevent them from dropping off, the weight of the exhaust muffler may increase and, since the structure becomes complex, the cost may increase.